A couple of months ago, I ran across a workaround for uploading photos to Blogger, but now I can't find the blog. If I find it, I'll give credit where it's due. Until then, if you are having problems uploading, here's a simple fix:
Go to: Google Page Creator
Login to your Google account, create a page, and upload the photos you would like to include on your blog. Once they're uploaded, click on the photo and copy the URL address. Go back to Blogger and create your post, click on upload photo, but rather than using "Add an image from your computer", use "Add an image from the web". Below that, there is a box where you will paste the URL address you just copied. Click on "Upload Image", and it will appear in your post.
This has saved me countless hours of wasting time waiting for an image to upload.